I use one box of Borax Laundry Soap to 50 gallons of water, this fills the trough I have with enough room for 2x4 and 2x6 materials to soak. My trough is 10 feet long, I mix the solution in the trough, add the wood I need to soak then add water to cover an inch over the wood.
I made my own trough by making wood ends and using caulk and screws to fasten/ seal these to a piece of flat roofing metal I got from a dealer who forms roofing metal at his shop.
I may build a second one eventually that is longer so I am not limited to the 10 foot length.
For chord wood I would buy a water trough (they can be bought in black rubberized material for around 60 dollars for a fairly large one) since you want your wood already cut to length when you soak it.
This is the site for the Tim-bor company products
tim-bor
I don't use it since the borax treatment works quite well for me, have not had any termite damage or fungus infection in any of the wood I have treated with it and most of this wood is in ground contact.
Redhawk